Stop and synchronized drive mechanism



May 26, 1942.

C. J. STUART STOP AND sYNcHRoNIzED DRIVE MECHANISM Filed Nov. 9, 1940 2 Sheets-Sheet l FITTI.

ATTOR NEY May 26, 1942. c. J. STUART 2,284,308

`STOP AND SYNCHRONIZED DRIVE MEOHANISM Filed Nov. 9, 1940 2 Sheets-Sheet 2 INVENTOR. J'zw mim 9. @M7

ATTORNEY Patented May 26, 1942 Charles J. Stuart, Medford, Mass., assgnor to Wellman Company, Me

tion of Maine dford, Mass., a corpora- Application November 9, 1940, Serial No. 364,963

5 Claims..

This invention relates to a stop and synchronized drive mechanism, more particularly as applied to blank cutting machines.

In the mechanical arts a large number of machines have been developed for cutting blanks of different types, and in the rubber footwear art there has been an extensive use of sole cutting machines of the type disclosed in the patent to McGowan No. 1,645,441. In machines of the McGowan type the stock is clamped between an upper pattern and a lower work table which is moved upwardly'to grip the stock, and while in this relation a knife is driven around the edge of the pattern to cut out the blank. In the Mc- Gowan machine the work table is raised by an air piston, and adjacent one corner of the work table there is a downwardly extending rod which carries an adjusting nut engageable with a nxed stop on the machine frame to limit the upward movement of the table. With every change in Q pattern or thickness of stock the operator must adjust the stop so as to clamp the work with just exactly the right degree of pressure, and the work table must bear evenly at all points against the pattern for proper cutting of the blanks. By reason of the central application of pressure from the air piston while the stop is located at one side of the center, di'iculty has been encountered in maintaining the level of the table so as to evenly clamp the work, particularly and slowing down the speed of cutting. Previously, therefore, the adjustment of the timing of the cutting mechanism with respect to the raising of the work table has been a hit or miss operation dependent solely on the experience and observation of the operator.

The present invention aims at a stop mechanism which can be quickly and readily adjusted and which can act without causing lateral strain yon the work table, and this result is accomplished by placing the stop mechanism centrally or axially of the work table and operating it ditable. While thisA stop mechanism is capable of independent use it is in the present invention also employed for the purpose of synchronizing the starting of the cutting mechanism with the clamping of the stock, and this result is accomplished by an air valve which is adjustably actuated by the stop mechanism and which in turn controls the clutch of the drive mechanism for the cutter. The adjustment of the air valve is so related to the stop mechanism that errors of judgment on the part of the operator are obviated.

`An object of the invention is to provide an improved stop mechanism for movable work tables which is easily adjusted, convenient to the operator while inspecting the operation of the table, and 'which will not in any way interfere with the proper levelling of the work table.

Another object is to provide a control mechanism for the actuating means of the cutting mechanism which can be adjusted by an unskilled operator, and which is synchronized with the stop mechanism so as to always start the cutting mechanism in desired properly timed relation with the movement of the work table.

Other objects will appear from the detailed description and drawings, in which latter Figure 1 is a broken-away front elevation of certain parts of a sole cutting machine,

Figure 2 is a detail, partly in section, of an air Valve for controlling the knife drive mechanism,

and

Figure 3 is a broken-away side View showing the connections between the air control valve and the knife drive mechanism of the machine.

Referring to the drawings, in Figure 1 there is shown a frame I in which is mounted a cylinder. 2 provided with a piston 3 which carries at its upper end the lower element 4 of a platen or work table 5, which elements 4 and 5 are connected by means of levelling screws 6 and l. Disposed on the work table is a backing sheet 8 upon which rests a sheet 9 of the stock to be cut, which sheet is clamped to the backing sheet and work table by the pattern I0, and at .II is shown a knife which cuts out the blank while moving around the periphery of the pattern. All

of these parts are substantially .as disclosed in the McGowan Patent No. 1,645,441. f

In place ofthe stop mechanism shown in Figure 2 of the McGowan patent the following mechanism is provided. Attached to the piston 3 rectly from the air piston used for raising the 55 is a tail rod I 2 upon which is threadedly mountedlimit the upward movement of the workrtable.

Secured to or integralwith the movable stop I3 is a pinion I5 which engages and slides on a long pinion I6 mounted on the machine frame, which Y air valve in casing 24 to permit the passage of air from the'main 25 through Vthel pipe 26jto'th`e cylinder 2, and upon release of the pedal 22 the valve in casing 24 also permits the exhaust of air Y from the cylinder, all of 4these parts being-substantially as shown in said McGowan patent. Connected to the air pipe 26 is a pipe 2'I govern ed bythe valve 23, which pipe leads into the upper I end of a valve casing 29 (Figure 2) provided withv a chamber 36. In this chamber there is movable a double headed valvef3I, the upper head 32 of which when seated shuts foi ingress of air 'to the valve casing, land by reason of the grooves 33 in the side of the valve airrcan enter the chamber 30, when the valve is opened. The lower'head 34 of thevalve is also provided with grooves at its side and when seated shuts Voli exhaust of air through the port 35. `Projecting from thevalve -3I throughthe port 35 is'a pin 36 having a bearing against a lever 31 pivoted at'38 on the valve casing,"and springs 39 attached to one end of the lever urge the valve 3l normally upward to a position closingv it against inlet of air and opening the exhaust port 35. At thev other end of the lever from the pivot 38, and equallyspaced therefrom with respect to the pin 36, is a contact screw 40 which is threadedly mounted in the end of the lever and -adjustably held bythe locknut 4I -It will be noted from Figure l that this `contact Screw 40 is in vertical alignment with the side of thepinion I5, and it is adapted to be engagedby the pinion I5, as will be later set forth.

At the side of the valve chamber 3B is a port 42 with which is connected a pipe-.43 leading into one side of the casing 44 which is divided centrally by a flexible `diaphragm 45. Attached Vto the diaphragm 45 on the opposite side is a rod Y 46 which is connected to a-piv-oted lever 41 which actuates the clutch ring 48. The clutch ring Vwhen moved by thelever -41 in v'one direction engages the shiftable Vclutch member 49 with its drive member 5I, the shiftable clutch member 49 being connected by a sprocket and `drive 5I) with the cutting mechanism of the machine in the manner disclosed in the McGowan patent. The drive member 5I of the clutch is connected by the `sprocket and chain mechanism 52 with a motor 53. Stop and lock .nuts 54 :are mounted on the rod 46 to limit the movement of the shiftable I member 49 of the clutch mechanism.

In use the operator by turning the hand wheel I9 adjusts the movable stop I3 .so that it will Contact with the fixed stop I4 at the .proper moment to permit the Work table to. clamp the Astock against the pattern with the desired .pressure, and as before pointed out `this adjustment must be made for every change in pattern or thickness of stock. The-hand wheel I 9 is located on the front of the machine so that the operator can readily operate it while watching the clamping action :of the work table, and by .means of fthe pointer 29 and index 2| he may readily 'ascertain at what point to adjust the movable stop I3. This `stop mechanism may 'be machines or others having the previous stop mechanism atv the corner of the Work table. It will be seen that the adjustment'can be readily and quickly made, it does not require the use of wrenches or lock nuts, and that by reason of its central location there Vis no tendency whatever to tilt the work table. when the latter is raised by the piston, thereby causing uneven` clamping of the work.

During the adjustment of the stop the valve 28 is turned to shut off the supply of air tothe valveY casing '29 so that the operator may raise and lower the work table without operating the cutting mechanism.v After the work table has Vbeen properly adjusted the valve 28 is then turned to open it so thatwhen the air is supplied to raise the piston it is atthe same time supplied to the fvalve' casing 29 for operating the cutting mechanism. It will be noted from an inspection of Figure 2 that the valve 3I is so constructed that a very small downward movement will completely open the valve for the admission of air to the chamber 30, andfor convenience this movement may be about le", but any other suitable dimension may be used.

To properly synchronize the operation of the cutting mechanism with that of the work table elevating mechanism the operator may raise the work table While inserting a le" gauge, if this is the extent of movement of the air valve, between the movable stop I3 and the xed stop I4. When the piston'has raised thek work table and thus clamped the gauge between the two stops, the

Y contact screw 49 is then adjusted until it `barely contacts the side of the pinion I5 and locked in such position by thenut 4I. Since the horizontal distance from the pivot .3i-J is the same to the contact screw'4l and the .pin 36 of the valve 3| it will be seenthat in operation when the Work table is raised the pinion I5 will contact the screw 40 one-sixteenth of an .inch or .other fixed distance' before the movable stop engages the fixed stop, and during the remaining movement of the stop I3 it will raise the screw Il!) while the opposite end ofthe lever vil will be moved downwardly against .the tension vof the .springs 39, thus permitting the valve 3l to fall by reason of gravity .and the :entering air under pressure and close the exhaust Sport 35. The air then passes through the pipe* 43, actuates 'the diaphragm 45, and through the rod "46 and lever 41 closes the clutch and 4starts the knife mechanism operating.

When the operator desires to .stop the machine hemerely releases the pedal '22 and through the valve iin casing 124, theair `in the cylinder .2 :and

441s exhausted thus'stopping the knife and Eallowing the work *table to drop. As soon as the work table beginsnto move downward, pinion I5 releases thepressure against contact .screw 40 thereby permitting the springs `39 to draw up the end of lever 31'so re-setting the valve in casing V29 toits closed position.

While in the present .embodiment the control of the operation, of `the clutch forthe .drive mechanism 4has been by Vmeansof compressed air, it is lobvious that in place of the valve casing 29 and associated parts an ordinary electric `contact switch might be substituted, andthis'might be used `to actuate amagnetic iclutch'in vplace of the clutchshown. 'In fact, anyequivalent velectri- .the various controls shown.Y

substituted on any of the present type-McGovvan75` n m11 vte seen that the` present invention has Vaccomplished a number of desirable improveaccenna ments in the operation of machines using movable work tables and drive mechanism for actuating machinery operating on materials or articles clamped on the work table, and it is not limited in its application to sole cutting machines. When the work table has been once properly levelled with respect to the pattern there will be no diiiiculty by reason of an eccentrically disposed table stop causing tilting when the table is raised. The adjustment for varying patterns or thicknesses of stock can be made quickly and accurately, and itl will be seen that the synchronizing of the work operating mechanism with the raising of the work table is made purely mechanical and requires no judgment or experience on the part of the operator.

Having thus described my invention, what I movable stop member for controlling the movement of said clutch.

3. In a work treating machine, a clutch-controlled main drive, a platen for clamping the work, means for actuating the platen,'stop mechanism for limiting movement of the platen and including a stationary stop and a movable stop actuated by the platen actuating means, clutch control means, and means for variably regulating y the timing of said clutch control means and actuated by said movable stop member.

4. In a work treating machine, a clutch-controlled drive means, actuating means for said clutch, work clamping means, actuating means for said work clamping means, and single adjustable means for limiting the stroke of said claim and desire to protect by Letters Patent is:

1. In a work treating machine, a drive means, means for clamping the work between two surfaces, `an adjustable stop device for controlling the distance between said surfaces when they are in the clamping position, and means actuated by said stop device for controlling the operation of said drive means in synchronism with the clam-ping of the work.

2. In a work treating machine, a clutch-controlled main drive, a platen for clamping the Work between it and a ixed member, means for actuating the platen, stop mechanism including fixed and movable stop members for limiting movement .of the platen in respect to said fixed clamping member, and means actuated by said work clamping means and synchronizing the clutch actuating means in desired timed relation withV the work clamping means.

5. In a blank cuttingmachine, cuttingmeans including a pattern, clutch-controlled drive means therefor, clutch actuating means, a reciprocable work table movable to clamp sheet stock against said pattern, means for moving said work table to `clamping position, a xed stop, a 

